Automatic Tranny-Service Life wit/without ATFchang

[Stewie]

Originally Posted By: HTSS_TR
Some manufactures make it very difficult to change lifetime transmission fluid, BMW is one of them.


Mazda is also one of them.

So how do you change it when the OEM fluid is not even available?

Originally Posted By: Nate1979
Just to clarify on these lifetime fills, do they require inspection at regular intervals?


It means it is completely sealed, for example in Mazda you would need to drop the pan to check the level and filter.

 

[CBR.worm]

I don't think you are supposed to check the level unless something happens, like you see evidence of a leak. In our ZF 6 speed auto, you are supposed to start the car cold and level, shift it through a couple gears, turn on the AC and pull out the fill plug. At some point between 40C and 50C ATF should start dripping out of the fill plug, if it does, put the plug back in and call it a day. If it doesn't, you need to put the plug back in, let the car cool down and start over - adding fluid so that it begins to run out around 40c.

What is interesting to me, is that ZF recommends changing the ATF at regular intervals in our 6HP22, I don't remember if it is 60K or 75K miles. BMW called it lifetime fluid. I had to do it myself as the dealer did not want to do it.

 

[kschachn]

Originally Posted By: Leo99
Originally Posted By: kschachn
Just because your two Toyota transmissions have made it as long as they have without a fluid change doesn't mean everybody else's Toyota transmissions will, nor does it mean another make would either. You are making a generalization that is unsupported by many manufacturers that recommend a regular fluid change.

I didn't make any generalizations and I never said anyone else's transmission would last as long as mine with the factory fill or recommend that people not change their fluid. I've just stated facts about my vehicles and what people have told me. You are reading things into what I've posted that are not there. I'm only talking about my two vehicles and my experiences with them. And the manufacturer of my vehicles doesn't recommend a regular fluid change for ATF.

I work in the science field and we have experimental groups and control groups. As an experiment, take N identical vehicles, operate half on the original ATF and operate half with regular changes. Drive them all to 300k miles and see if anything statistically significant happens.


Well OK you are right, you don't suggest outright that other people's transmissions would last as long. I just have seen you post your comment multiple times and I guess I took that as you were advocating the practice. When people repeat things multiple times it generally means they are promoting the ideal but not in this case.

And I too worked in the science field for many years as a research technologist for a large corporation, so I know about the scientific method. The problem is that I haven't seen such a test performed nor have I seen the results, have you? And are you claiming that your basis for your claims:

Quote:
There were two experts. One owns his own general repair shop and has been in business 10+ years. The other guy owns a transmission shop and has been in business for 42 years.


Meets the criteria?

 

[2004tdigls]

this explains everything about "life time transmission fluids"

http://forums.vwvortex.com/showthread.php?1064342-Heads-up-VW-Lifetime-auto-transmission-fluid-(baloney!!!)

 

[jrmason]

Again, even "lifetime fill" transmissions have SOME way of being able to check the fluid. It is generally beyond the scope of the average shade tree mechanic but there is something there to allow the tech to monitor the fluid level when filling the trans in the event the pan has to come off....or for the new reman unit going in because the original trans found the service limit of the "lifetime" fluid.

Since transmissions dont use or burn fluid, the only real inspection necessary between service intervals is to ensure there are no leaks anywhere.

 

[Leo99]

Originally Posted By: kschachn
Originally Posted By: Leo99
Originally Posted By: kschachn
Just because your two Toyota transmissions have made it as long as they have without a fluid change doesn't mean everybody else's Toyota transmissions will, nor does it mean another make would either. You are making a generalization that is unsupported by many manufacturers that recommend a regular fluid change.

I didn't make any generalizations and I never said anyone else's transmission would last as long as mine with the factory fill or recommend that people not change their fluid. I've just stated facts about my vehicles and what people have told me. You are reading things into what I've posted that are not there. I'm only talking about my two vehicles and my experiences with them. And the manufacturer of my vehicles doesn't recommend a regular fluid change for ATF.

I work in the science field and we have experimental groups and control groups. As an experiment, take N identical vehicles, operate half on the original ATF and operate half with regular changes. Drive them all to 300k miles and see if anything statistically significant happens.


Well OK you are right, you don't suggest outright that other people's transmissions would last as long. I just have seen you post your comment multiple times and I guess I took that as you were advocating the practice. When people repeat things multiple times it generally means they are promoting the ideal but not in this case.

And I too worked in the science field for many years as a research technologist for a large corporation, so I know about the scientific method. The problem is that I haven't seen such a test performed nor have I seen the results, have you? And are you claiming that your basis for your claims:

Quote:
There were two experts. One owns his own general repair shop and has been in business 10+ years. The other guy owns a transmission shop and has been in business for 42 years.


Meets the criteria?



I don't advocate lifetime fluids nor do I advocate changing them out periodically because I just don't know. I don't have any data to support either position. Do you? It comes back to are there data to show that changing out so-called lifetime fluid extends the life of the systems compared to systems were the lifetime fluid was never changed?

I'm still waiting to see this data.

 

[DB_Cooper]

See the link for a data point:

ZF suggests changing lifetime fluids

ZF suggests changing the "lifetime" ATF at 62000 miles (or eight years) if you drive "spirited", "special environmental considerations" or put additional loads on the transmission. Other than that they stand behind the "lifetime" recommendation.

The ZF transmissions need service 62000 miles to infinity depending on how you drive, how hot or cold it is and how many hills you go up and down.

A regular ATF and filter service seems like a good idea to me.

 

[demarpaint]

Originally Posted By: DB_Cooper
See the link for a data point:

ZF suggests changing lifetime fluids

ZF suggests changing the "lifetime" ATF at 62000 miles (or eight years) if you drive "spirited", "special environmental considerations" or put additional loads on the transmission. Other than that they stand behind the "lifetime" recommendation.

The ZF transmissions need service 62000 miles to infinity depending on how you drive, how hot or cold it is and how many hills you go up and down.

A regular ATF and filter service seems like a good idea to me.


Lifetime makes me laugh. ZF should just state service intervals and be done with it.

 

[Nate1979]

The words cheap insurance get thrown around a lot, probably to much. But for those crying about lack of data its not like the OEMs are just going to release all their proprietary and trade secrets. Regardless why is it such a big deal to spend a few hundred dollars with a few drain and fills to possibly extend the life of the transmission which cost thousands to rebuild. Its all about risk reduction.

 

[pocketchange]

I've been on the side of servicing ATs whenever the fluid sample indicates it's time.

ZF.. recently, were in favor of lifetime (no service as I read it). Then again ZF along with every AT builder has one agenda (if you don't understand this, it would be good to find a shady spot and stay there.)

Nice that ZF got around (at least) to their fluid changing policy. My A8 gets serviced every 65/70K (which has been 7 years) and the fluid/filter were in average/good condition as the sample indicated. I'm now @ 135K and serviced 2nd time per sample results (average/good.. again).
At $3,500 to rebuild, I'll continue with sampling and service. It works for me.
pc

 

[Whitewolf]

In my experience the 'dirtiest' a transmission ever is (apart from catastrophic failures) is when it's new. Once the first lot of fluid has been drained after some reasonable mileage, as long as you use the correct OEM recommended fluid, you will probably never need to change it again.

 

[exranger06]

Originally Posted By: Whitewolf
In my experience the 'dirtiest' a transmission ever is (apart from catastrophic failures) is when it's new. Once the first lot of fluid has been drained after some reasonable mileage, as long as you use the correct OEM recommended fluid, you will probably never need to change it again.

I strongly disagree. I dropped the pan on my Ranger when it had about 25k miles. It looked spotless and there was almost no sludge anywhere on the magnet or pan. I dropped the pan on my Explorer when it had 145k miles (about 85k miles since its last trans service) and it had significant sludge on the magnet and all over the pan. It was definitely WAY dirtier than my almost-new Ranger trans. And the Explorer was not experiencing catastrophic failure either. It now has 196k miles and it's still shifting perfectly.

 

[Stewie]

Not changing the ATF will cause you have to rebuild transmission due to clutch pieces diluting in ATF

 

[147_Grain]

.....and the abrasive clutch material will accelerate the wear and tear of all transmission components.

You can pay me a little now (with preventive maintenance) or a lot ... later (with a new transmission).

 

[SteveSRT8]

Whitewolf's assertion is well documented. A typical slushbox will generate far more debris in the first part of its life than the latter stages assuming all else is well. I have seen this in my fleet trucks for decades.

Stewie: note that the filter actually is quite lousy in most transmissions, more of a "rock catcher" than anything else. As it becomes filled with debris it will actually filter better. But of course some designs do not like a restriction in the flow.

If clutch fragments killed transmissions they would all die very quickly...

 

[KevinV]

Originally Posted By: KevinV
I just bought a2001 BMW 325i. Its our first car with an automatic. It shifts well but has never had an ATF change. I'm wondering what's the average life of a ZF automatic transmission with or without regular ATF changes. The car has been driven with care. Any votes for just letting the automatic transmission alone and not changing it ? I also wonder how much a replacement transmission (God forbid) would be if it ever came to that.


A BMW mechanic told me to check the automatic transmission control module's ranges and if the "adaptations" are within range (meaning no signficant wear has occured), it would be ok to change the ATF even at 150K miles. Otherwise if they are outside of range, don't change the fluid. Has any one experience with this process and any opinions ?

 

[KevinV]

Originally Posted By: KevinV
Originally Posted By: KevinV
I just bought a2001 BMW 325i. Its our first car with an automatic. It shifts well but has never had an ATF change. I'm wondering what's the average life of a ZF automatic transmission with or without regular ATF changes. The car has been driven with care. Any votes for just letting the automatic transmission alone and not changing it ? I also wonder how much a replacement transmission (God forbid) would be if it ever came to that.


A BMW mechanic told me to check the automatic transmission control module's ranges and if the "adaptations" are within range (meaning no signficant wear has occured), it would be ok to change the ATF even at 150K miles. Otherwise if they are outside of range, don't change the fluid. Has any one experience with this process and any opinions ?

 

[caravanmike]

Originally Posted By: KevinV
Originally Posted By: KevinV
I just bought a2001 BMW 325i. Its our first car with an automatic. It shifts well but has never had an ATF change. I'm wondering what's the average life of a ZF automatic transmission with or without regular ATF changes. The car has been driven with care. Any votes for just letting the automatic transmission alone and not changing it ? I also wonder how much a replacement transmission (God forbid) would be if it ever came to that.


A BMW mechanic told me to check the automatic transmission control module's ranges and if the "adaptations" are within range (meaning no signficant wear has occured), it would be ok to change the ATF even at 150K miles. Otherwise if they are outside of range, don't change the fluid. Has any one experience with this process and any opinions ?
maybe this mechanic is talking about the clutch value indexes (CVI's)

 

[philipp10]

Originally Posted By: kschachn
Just because your two Toyota transmissions have made it as long as they have without a fluid change doesn't mean everybody else's Toyota transmissions will, nor does it mean another make would either. You are making a generalization that is unsupported by many manufacturers that recommend a regular fluid change.


I can easily flip that around and say just because you know of a failed transmission on the FF then that actually means something. I have said, and still say, Toyota would not make a recommendation of filled for life without good data saying it makes sense. My opinion is that unless you over-heat the fluid, there is no reason to change it. I wish there was some real, hard and accurate data that could be accessed rather than all the ancedotal [censored] given here.

 

[philipp10]

Quote:
There were two experts. One owns his own general repair shop and has been in business 10+ years. The other guy owns a transmission shop and has been in business for 42 years.


Meets the criteria?

two transmission repair shops? I don't think so. That's about as biased as it can get.